Extractable plastic cartridge

ABSTRACT

A PORTION OF A DEFORMABLE CASING IS PERMANENTLY DEFORMED BY THE EXPLOSIVE GAS PRESSURE OF THE CARTRIDGE AT FIRING TO FORM RIM MEANS ON THE OUTER PERIPHERY THEREOF. THIS RIM MEANS ON THE OUTER FUNCTION AS A POSITIVE GAS SEAL, TO EXTRACT THE CARTRIDGE FROM THE CHAMBER, DEPENDING ON THE RECESS INTO WHICH THE RIM IS DEFORMED, AND/OR TO PREVENT THE CARTRIDGE CASING FROM BEING EXPLOSIVELY EXPELLED FROM THE CHAMBER.

Get. 5, 1971 J. J. SCANLON EXTRACTABLE PLASTIC CARTRIDGE 5 Sheets-Sheet1 Filed May 7, 1969 Inventor'- Jehh d. Seaman Attorneys Oct. 5, 1971 J.J. SCANLON 3,609,904

EXTRACTABLE PLASTIC CARTRIDGE Filed May 7, 1969 3 Sheets-Sheet 2 3K i 7]//%//i I W f fig Oct. 5, 1971 J. J. SCANLON ,609,

EXTRAC'IABLE PLASTIC CARTRIDGE Filed May 7, 1969 3 SheetsSheet 3 Inv r:John Q. anlon Attorney United States Patent 3,609,904 EXTRACTABLEPLASTIC CARTRIDGE John J. Scanlon, Monroe, Conn., assignor to RemingtonArms Company, Inc., Bridgeport, Conn. Filed May 7, 1969, Ser. No.822,498 Int. Cl. F42c 21/12; F42b /30 US. Cl. 42-76 2 Claims ABSTRACT OFTHE DISCLOSURE This invention relates to a broad new concept inammunition design which utilizes the explosive gas pressure generated bythe firing of a cartridge to deform a portion(s) of a deformablecartridge casing to effect one or more functions.

In general, the invention relates to an extractable cartridge casingwhich has some of the advantages of an expendable case while retainingsome of the advantages of an extractable case. More specifically, theinvention relates to the concept of using explosive gases generated byfiring of a cartridge to permanently deform a portion of a deformablecasing into a gap, groove, or recess means in the gun chamber thusforming an outwardly projecting rim portion which interengages with thegap, groove, or recess means in the gun chamber to effect one or morefunctions such as gas sealing, extractor means, or stop means preventingthe cartridge casing from being explosively expelled from the gunbarrel.

The present invention is an outgrowth of applicants work with expendablecartridges wherein deformable plastic casings are designed to beexplosively expelled from the bore of the gun along with the projectilemeans. It was found that for some uses it was desirable to provide anextraction and ejection cycle in order to guarantee a clear chamberafter each cycle, e.g., for aircraft firing systems where jet enginescannot digest any foreign particles without severe consequences.

Under the present invention, the cartridge would still have some of theadvantages of the expendable case cartridge, i.e., light weight, lowcost, and a non-vulnerable cartridge. An additional advantage is thereplaceable obturator concept wherein the gases are sealed by thecartridge casing and since the cartridge casing is replaced for eachfiring, in effect a new obturator is used with each firing. The presentinvention is not intended to supplant the expendable case concept. Bothtypes of ammunition could be used for different applications. Forexample, the extractable casing would not be suitable for tanks where itis desirable not to have empty ammunition cases in the confined areainside the tank. Aircraft could use the extractable plastic casingswhile ground troops could use either the expendable or extractablecasings.

An object of this invention is to provide a low cost, extractable,cartridge casing.

Another object of this invention is to utilize the explosive firing gaspressure to deform a portion of a shell to perform one or more necessaryfunctions of the firing system.

Other objects and advantages will be apparent after reading the appendedclaims and the following description in which:

FIG. 1 shows an elevation view in cross-section of a center fire typeextractable cartridge as envisioned by the present invention;

FIG. 2 shows a side View of the cartridge of FIG. 1 in firing positionin an associated gun;

FIG. 3 shows a schematic view of a modified exgactable cartridge inposition in a gun chamber before ring;

FIG. 4 shows a schematic view of the modified extractable cartridgeshown in FIG. 3 in a gun chamber after firing;

FIG. 5 shows an elevation view in cross-section of a shotshell typeextractable cartridge which can be used in the present invention; and

FIG. 6 shows a schematic side view of a shotshell, of the type shown inFIG. 5, in position in the gun chamber after firing.

FIG. 7 shows a schematic view of the plastic shell of pending US.application Ser. No. 686,508 in position in a gun chamber before firing.

Referring to the drawings, FIG. 1 shows a cartridge 10 having atwo-piece casing 12 and a projectile 14 extending forwardly from thefront or month end of the cartridge. Casing 12 includes a forward neckportion 16 which tapers to a smaller diameter at the mouth end 18 inwhich the projectile 14.can be secured by any wellknown conventionalmeans such as interference fit, adhesive, etc. The neck portion 16 isattached to the forward end of a tubular body portion 20 by a rim andgroove means 22 or by any other well-known means. The rear or breech endof the tubular body portion 20 is closed off by a transverse end wall 24which has a central recess 26 formed therein to define a narrower wallsection 28 through which a stab-type firing pin 30 (see FIG. 2) caneasily be projected. An extractor groove means 32 is formed on the outerperiphery of the tubular body portion to engage with an extractor ring34 formed on the forward end of a shrouded bolt means 36.

The bolt means 36 is slidable mounted in a receiver 38 and has a boltchamber means 40 which cooperates with an axially extending gun chambermeans 42 in the gun barrel 44 to accommodate and support the cartridge10. The gun chamber means 42 communicates with an axially aligned boremeans 46 through which the projectile is explosively expelled.

The rear end of the gun chamber 42 and the front end of the bolt chamber40 are separated by a distance or annular gap 48 to be described later.

Positioned within the cartridge 10 is a loose or molded propellant 50located within the neck portion 16 and a main molded propellant means 52in the tubular body portion 20. A recess 54 is formed in the rear of themolded propellant 52 to receive and support a combustible primer 56.Obviously, the main propellant 52 can also be in loose or liquid form inwhich case the primer means would have to be altered in order to holdthe primer in position and protect it from the environment.

As mentioned previously, FIG. 2 shows a stab-type firing pin 30 whichmust be able to be projected through the thin wall section 28 in orderto strike the primer 56. Upon ignition, the propellant means 52 and 50are ignited whereupon the combustion gases expel the projectile 14through the gun barrel 42 and out of the muzzle.

The cartridge casing, whether of one-piece or twopiece constructionpreferably, is made of plastic material, such as polyethylene,polypropylene, polycarbonates, etc., although it is obvious that adeformable metallic material such as copper, brass, aluminum, or steelcould be used also. The limiting criteria, of course, is

that the material must be capable of being deformed into the gap,recess, etc. The tubular body portion 20 particularly must be made of adeformable material, which upon firing, will deform into the annular gap48 to form a permanent rim means 58 (not shown in FIGS. 1 and 2). Therim means will function as a positive gas seal to prevent gas leakagewhich may work back between the outer periphery of the cartridge casingtubular body portion 20 and the inside wall 42a of the gun chamber means42. Without the rim 58, the explosive gases would leak through the gap48 formed between the gun chamber means 42 and bolt chamber means 40.

A second function of the rim in FIGS. 1 and 2 is to act as a stop meansto limit axial movement of the casing tubular portion in the gun chamber42 after firing. The extractor function in FIGS. 1 and 2 is met by theextractor ring 34 and groove 32.

It is noted that the firing system shown in FIG. 2 is a self-obturatingsystem and that the firing pin is self-sealing. The bolt can be sealedalso for additional protection. See applicants pending application Ser.No. 789,233, filed Jan. 6, 1969, for one such type of firing pin andbolt sealing means.

FIG. 3 shows a modified one-piece cartridge casing 60 made of deformableplastic material as explained above. The rear end of plastic casing 60is closed off by a plastic base cup 62 which has a central recess 64similar to recess 26 in FIGS. 1 and 2. A molded propellent charge 66having a recess 68 for a combustible primer 70 are similar to that shownfor FIGS. 1 and 2. FIG. 3 also shows the shrouded bolt means 36 ashaving an extractor groove means 72 into which the deformable plasticcasing is explosively and permanently deformed upon firing to form anextractor rim 7-4 on the outside periphery of the casing 60. (See FIG.4).

FIG. 4 shows the system of FIG. 3 after firing. The extractor rim 74 andgroove 72 permits the cartridge casing to be withdrawn from the gunchamber. It will be necessary to provide other means in order towithdraw a loaded or unfired round from the chamber. At the same time,upon firing, the casing 60 is permanently deformed at gap 48 to formannular rim 58 which acts to limit axial movement of the cartridgecasing as well as to seal off the explosive gases.

FIGS. and 6 show that the concept of the present invention can also beapplied to shotshells. FIG. 5 shows a shotgun shell 76 having adeformable plastic tubular body member 78 in which the mouth end 80 iscrimped or closed 01f in any conventional well-known manner. The breechend of the tubular body member is closed off by a plasticpropellant-primer cup 82 having a central recess 84 through which astab-type firing pin, as explained above, moves. The plastic cup 82 isattached to the body by any Well-known means such as the snap-in rim andgroove means 86 shown in FIG. 5. An annular support flange 88,integrally formed with the inside wall of the body casing 78, supports amolded propellant charge 90 and a wad column-shot container 92. Shotpellets 94 are located within the shot containing portion of the wadcolumn 92. Obviously, any wad type of wad column can be used withoutaffecting the invention. Finally, an extractor groove 96 is found on thebreech end of the tubular body member 78.

FIG. 6 shows the plastic shell of FIG. 5 after firing in which apermanently deformed rim 98 is extruded into the split chamber gap 100,as explained previously.

FIG. 7 shows the plastic shell shown in pending application Ser. No.686,508, filed Nov. 29, 1967, in the gun chamber similar to that shownin FIG. 3 of the drawings.

Shell casing 102 has a transverse wall means 104 which may beimperforate or which may have an opening therethrough. The drawing showsa blind hole 106 but as mentioned in pending application Ser. No.686,508, openings have been used successfully. A projectile 108 ispositioned in the front end of casing 102 and a propellant means 110 ispositioned in the opposite end of the shell. A priming means 112 ispositioned in the propellant means and in caused to be ignited by theimpact of firing pin 30.

The plastic shells of FIGS. 1 to 6 differ from FIG. 7 in that they showa wall means to close off the rear or breech end of the shell so thatupon firing, the explosive propellant gases act against this wall toprevent the shell casing from being expelled through the gun barrel. Therim means formed in these designs, while they may assist in keeping theshell casing in the gun chamber, are not the primary reason for theretention of the shell casing in the chamber. In FIG. 7 there is notransverse wall means at the rear end of the shell casing to act againstand thus, the rim means which is formed in this instance is the primarydeterrent to expulsion of the case. The gas sealing function of thedesigns in all cases is the same.

Obviously, other types of plastic shells can also be utilized inexercising the invention, such as the plastic casings shown in pendingapplications Ser. No. 868,508, filed Nov. 29, 1967, and Ser. No.755,649, filed Aug. 27, 1968. Also other combinations of propellantmeans and priming means are possible.

What is claimed is:

1. A firing system comprising a gun barrel having a receiver meansattached at the breech end thereof, an axially extending bore in saidgun barrel, a chamber means formed in the breech end of said gun barreland communicating with said bore at the front end and with the receivermeans at the rear end, a cartridge having a deformable casing beingpositioned in and supported by said chamber means, recess means in saidchamber means into which said deformable cartridge casing is explosivelydeformed so as to seal the explosive gases from escaping past thecartridge to said receiver means, separate extractor means provided toextract the cartridge casing from the gun chamber, said extractor meanscomprising a groove means formed in the side wall of said cartridgecasing and lug means integrally formed with an axially reciprocating gunbolt, said lug means engaging said groove means either before firing ofthe cartridge or after firing to enable the reciprocating bolt to movethe cartridge casing into and out of the gun chamber.

2. A firing system as recited in claim 1 wherein said chamber means is asplit chamber consisting of a gun barrel chamber portion and a gun boltchamber portion, at least a portion of the breech end of the deformablecartridge casing being supported by an overlapping end portion of areciprocating bolt means to form a gun bolt chamber portion, said recessmeans comprising the space between the forward end of the bolt chamberportion and the gun barrel chamber portion.

References Cited UNITED STATES PATENTS 1,165,621 12/1915 Nelson '891802,925,014 2/ 1960 Abramson 891.706 2,987,965 6/1961 Musser 891.7063,048,849 8/1962 De Caro et al. n 10253 X 3,485,1'70 12/1969 Scanlon10243 X ROBERT F. STAHL, Primary Examiner U.S. Cl. X.R. 102-43 P

